The move, which will be completed by the end of June and is worth up to €850m, means that 3 will become the country's second biggest operator with more than two million customers.

It will also see venues such as the O2 in Dublin, formerly known as the Point Depot, renamed again and sports sponsorships for the Irish rugby team rebranded.

However, Ireland's own communications regulator remains dissatisfied with the ruling, warning of "significant negative consequences for Irish consumer welfare".

A spokesman said that the compromise deal "appears inadequate and ineffective to address the serious competition concerns and consumer harm identified by the European Commission, for example higher prices".

But fears of higher prices for mobile phone customers have been eased as the European Commission insisted that the deal could only proceed if 3 Ireland helps to set up two new 'virtual' mobile operators that have access to its network.

The Irish Independent understands that UPC is in the final negotiating stages of setting up the first such mobile operator.

A second operator is expected to be set up in the coming months.

Meanwhile, job losses at O2 Ireland could result from the takeover, according to 3 Ireland's chief executive, Robert Finnegan.

"Inevitably when you're merging two companies, there will be duplications and we will have to eliminate some positions," he said. "But there will also be opportunities for new jobs."

The deal will put the new post-merger operator just behind Vodafone, at 37pc of the Irish market. It will also bring 3 closer to profitability, with the company having sunk a cool €1.1bn into its loss-making Irish operation in its 10-year stint here.